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ATC Tutorial

7,639 bytes added, 09:42, 10 May 2008
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lesson 5 added, table made more readeble
''See also [[ATC]]for the main article''
== Introduction ==
Air Traffic Control is an agreed procedure and process which keeps the aircraft separated to ensure that they don't crash into each other or are affected by turbulence when passing through the same air space. The separation of planes taking off or landing at airports is three minutes. This allows the air to settle again. Pilots have used an analogy of calling the atmosphere soup as air and liquid has similar properties.
Air Traffic control is an agreed procedure and process which keeps the aircraft separated to ensure that they don't crash into each other or are affected by turbulence when passing through the same air space. The separation of planes taking off or landing at airports is three minutes. This allows the air to settle again. Pilots have used an analogy of calling the atmosphere soup as air and liquid has similar properties. In order to be able to effectively and reliably communicate, ATC and pilots agree on a set of keywords and jargon. This may vary between regions and the like. English is the agreed language for internaltional flights. (Could someone check if this it eh is the case?) 
==Lesson 1==
|Controls the movement of aircraft on the ground at an airport, however only the taxiways and bays... not the active runways. Whenever a plane needs to cross an active runway, it has to call the tower.
|-
! bgcolor="#386386EFEFEF" align="left" |xxxx_TWR! bgcolor="#386386EFEFEF" align="left" |Tower Controller! bgcolor="#386386EFEFEF" align="left" |'Owns' the runways and the airspace until 10 NM (nautical miles) from the airport. Clears planes for takeoff and landing.
|-
|xxxx_APP
|Controls the airspace up to 30NM away from the airport, up to 18,000 ft (usually). Handles all aircraft leaving or arriving at an airport, until they are established on the ILS (then gives the plane to TWR) or are leaving their airspace to continue flight (then hands off to CTR)
|-
! bgcolor="#386386EFEFEF" align="left" |xxxx_DEP! bgcolor="#386386EFEFEF" align="left" |Departure Controller ! bgcolor="#386386EFEFEF" align="left" |An position rarely used except at busy airports in the real world which relieves the work-load of the approach controller by handling all the departures, and getting them away from arrivals as quickly as possible, leaving the approach controller free to handle arrivals (the hard bit).
|-
|xxxx_CTR
|Centers own all airspace not controlled by APP or TWR. They control the plane while en route, and get it from X to Y safely, until it can be descended and given to the approach controller.
|-
! bgcolor="#386386EFEFEF" align="left" |xxxx_FSS! bgcolor="#386386EFEFEF" align="left" |Flight Service Station! bgcolor="#386386EFEFEF" align="left" |Flight Service Stations cover large areas (e.g.: France) and provide support to pilots and controllers. They can advise pilots of weather and frequencies for other controllers. They do not provide Air Traffic Control.
|-
|xxxx_DEL
I'm not sure how we ended up at Heathrow, but that's another story!
 
==Lesson 5==
Our plane, B-ELIO, is now about 40NM east-south-east of Heathrow ready to start the approach to runway 9L - as tower has chosen runway 9R for departures, with the winds of 87@22 - the plane is at 18,000 ft and is heading at 270 (towards the left of our screen...).
 
Did you remember that the landing direction would be towards the right of the screen? I hope so... Anyway, planes need to be at 2,500 ft about 8NM away from the airport heading in the correct direction to intercept the magical [[ILS]] device that will guide them perfectly onto the runway. We know we need to keep the plane at 8,000 ft until its past OCK, and then get it down to 2,500 and onto the grey dotted line leading to the left runway (9L) for the ILS and tower to take the passengers safely to the ground. Formulate a plan: accept the hand-off, descend the plane to 8,000 and send it directly towards OCK VOR, at OCK descend it to 2,500 and fly it past OCK on 270, then turn it to 360 (north, easier to read than '0') up the grey dotted line pointing north, then turn it to 45 so that is cuts the grey-dotted line at 90 to runway 9L... when the plane is on a course taking it through extended center-line (an imaginary line representing a line extending from the runway) it is said to be intercepting the localizer. The plane can then be told to get itself onto this extended center-line as the ILS will warn the plane when it needs to turn to establish itself on the line.
 
Since the airplane is on the wrong side of the airport, we fly three sides of a rectangle, the first is known as the down-wind (since you land heading up-wind), then the next 'leg' is known as the base, and the red-line shows the final. If the plane was coming from the west, he could just fly a 'straight-in' approach, also known as an extended final - as the plane only flies a very long final.
 
The orange line shows the 'intercepting the localizer' as the plane will continue to fly this heading until the ILS tells it to turn right onto the center-line of the runway. As soon as the plane reports it's established on the localizer (it has direction signals), it can be cleared for the approach and told to descend with the glideslope which gives the plane height signals. The glideslope and localizer give precision approach information and are known - together - as the ILS (Instrument Landing System). Then get the plane to the tower, because - remember - you may well be dealing with planes taking off which you need to get out of your air-space, and other planes trying to get established on the ILS, as the tower wants a steady stream of well-separated planes on the ILS. You hopefully now know what you're supposed to be doing, but how do we do it. We'll look at each stage in turn.
 
'''B-ELIO: B-ELIO with you at 18,000 for Heathrow. Information Alpha. (Your ATIS - might contain weather, voice IP?)'''
 
'''You: B-ELIO, Radar Contact, alpha is current. d/m 8,000 and direct OCK please.
 
B-ELIO: rgr, down to 8,000 to OCK.'''
 
 
Great... B-ELIO will now get to OCK and be at 8,000. Just before he gets to OCK, you need to issue the next instructions so that he can be ready for them:
 
'''You: B-ELIO, d/m 2,500 continue present heading and expect ILS approach to runway 9L at Heathrow
 
B-ELIO: rgr, 2,500 on my heading for 9L, B-ELIO.'''
 
OK so far? Now let's head him towards the airport. This is the base leg:
 
'''You: B-ELIO, turn right heading 360 (for base) the for base is for information and is usually left out.
 
B-ELIO: t/r (turn right) 360, B-ELIO'''
 
This is where judgment and cunning use of the feature for monitoring heading and distance come into play. It is also your duty to give the plane the frequency for the ILS (in the form xxx.xx) which can be found at www.ivao.aero/db/ss (or from database, sector system) using the search facility. The plane just hit the extended center-line at least 8NM away from the airport, so make sure you issue the turn to 45 at the correct time, otherwise B-ELIO will miss the ILS. Right place, so...
 
'''You: Turn right heading 45 to intercept the localizer on 119.21 to 9L and report established
 
B-ELIO: right to 45 for LLZ to 9L, will report established
 
B-ELIO will now get himself onto the localizer and call:
 
B-ELIO: established'''
 
This is your cue to clear him for the approach and allow him to descend (otherwise he'll fly perfectly over the runway at 2,500ft). This is done with the following command:
 
'''You: B-ELIO, rgr (I heard the 'established') cleared the ILS approach to 9L, descend with the g/s.
 
B-ELIO: Cleared ILS approach
 
You: B-ELIO, contact the tower on 118.52 (if there is a tower, else you'll have to do the job... and look up the tower frequency in who's on-line)
 
B-ELIO: Over to the tower, thanks for your help.'''
 
That's your job done! As the approach controller you have the most work, so don't be afraid to give planes holds. A hold is a request for a plane to circle around a given fix (e.g.: a VOR) at a given height until you can do something with them. In fact, if you have lots of planes all circling a VOR, it's known as a 'stack' because the plane's are stacked there. So, we could get three planes holding at the OCK VOR (while we waited for traffic to decrease) at 6,000 ft, 8,000 ft and 10,000 ft and add new planes to the top and take planes ready for the approach from the bottom. To give a hold, the basic command is:
 
''Hold at <vor name> VOR at <current altitude/10,000 etc. / FL120 etc.>, expect further clearance in <time> minutes.''
 
Which requests the pilot flies around the <vor name> VOR at the assigned altitude until you give him a new clearance. The expect further clearance (e.g.: expect further clearance in 10 minutes) just gives the pilot some idea of the delay and does not give the pilot the right to start flying away after that time is over! The full clearance for holding is as follows, but usually you can just use the one above unless you specifically need to avoid a plane coming to a certain side of the VOR:
 
'''Hold <north/east/south/west> of the <vor name> VOR on the <approach heading> radial, expect further clearance in <time> minutes.'''
 
The approach heading is the heading at which you want the plane to approach the VOR. So, hold north of the OCK VOR on the 270 radial would ask the pilot to fly to OCK on a hdg of 270 and then to hold so he's always north of the fix. A hold is a racing track shaped rectangle.
 
The key to remember as the approach controller is to, wherever the planes coming from, remember its height is just as important as its direction when it comes to landing - 2,500 ft (above ground level) for the ILS.
 
Disaster! You've got a propeller aircraft doing an approach and you've started a 747 on the same approach behind it. There's nothing to hold it at, and there getting very close -- what do you do? You could take the plane away and start the approach again, but using an orbit -- a circle to the left or right and then on the original heading -- will increase your time, just give:
 
'''You: B-ELIO, one orbit to the left please for spacing.
 
B-ELIO: wilco'''
 
Also, sometimes as approach you will want to slow a plane down to ensure that it isn't conflicting with a plane already on approach in front... if they are too close, the second plane will end up missing his approach because the plane in front will still be on the runway.
 
'''You: B-ELIO, slow to 210kts
 
You: B-ELIO, slow to minimum feasible speed please
 
You: B-ELIO, maintain minimum 190kts ''etc.'''''
 
Anyway, back to our imaginary flight in which B-ELIO is flying the approach and is back with the tower...

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